Electronic counter



L. R. HARPER ELECTRONIC COUNTER 2 Sheets-Sheet l OUTPUT OUTPUT 3nventorLEONARD R. HARPER (Ittomeg INPUT ICON" IOOV Jan; 17, 1956 Filed- Dec.21, 1950 DIO FIG. 3

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L. R. HARPER ELECTRONIC COUNTER Jan. 17, 1956 2 Sheets-Sheet 2 FiledDec. 21, 1950 OUTPUT:I

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r OR T Ll m u mu w w M O O W 0 01 W O 3H 3 4 06 '06 R O D 3 OT T R 0 OTA o o o o o o M E o L v n 3 3 6 9 o f o 5 0 ll 2 0 R 4 2 3 OT OT OT 0 Q0 O 3 O 3 m D 5 .O O 3 0 0|.[ u R 1 5 n 0 0T 3 o o o o o o C m D 2 I O 3I.. 0 1 0L 0 O (Ittorneg United States Patent ELECTRONIC COUNTER LeonardR. Harper, Poughkeepsie, N. Y., assignor to International BusinessMachines Corporation, New York, N. Y., a corporation of New YorkApplication December 21, 1950, Serial No. 202,120

36 Claims. (Cl. 235-92) The present invention relates to counterscomprising cascade connected electronic triggers and more particularlyto means for changing the normal cascade operation of such a series oftriggers to operation in the decimal or duo-decimal radix.

in the prior art it is well known to employ a plurality of Eccles-Jordantype triggers connected in cascade as the basis of an electronic counterbut these have necessitated means for altering the normal cascadeoperation in order to produce operation in a chosen radix such as, forexample, decade or duo-decimal operation, among others. These alteringmeans have fallen into two chief classes. One class employs feedbackmeans whereby the normal cascade operation of a chosen trigger isblocked and certain counts are eliminated. The feedback permits partialflipping of a trigger but prevents complete flipping of the triggerunder operation of counter entry pulses received. This inherentlydecreases the maximum speed of operation. in another method of the samegeneral class, a blocking tube is utilized in addition to the tubes ofthe regular triggers which blocking tube is controlled by this feedbackand in turn controls a trigger whose flipping in the normal order ofcascade operation is thus prevented. In these devices of the prior art,the-trigger controlled always entered itself, into the blockingoperation.

In a second class of devices of the prior art, certain triggers of thecascade were unnecessarily flipped out of the pure cascade order inorder to achieve conversion to a desired radix.

in both these classes, in the prior art, the maximum number of triggerswhich are flipped toachieve an output pulse at any one time comprisedthe total number of triggers employed in the cascade. Anotherdisadvantage in the prior art employing feedback correction lay in thefact that this feedback utilized a full plate instead of a plate tap, ordirect connections to a grid were employed, both types of theseconnections being very unstable.

It is, therefore, one of the objects of the present invention to avoidthese disadvantages of the prior art by avoiding each of the operationsset forth specifically above. These means comprise generally a diode, A.C. coupled on its output to a trigger which is selectively operated ornot operated depending upon the relative on and off conditions of twoother triggers of the cascade. This is in direct contrast to theutilization of D. C. coupled diodes which are employed in feedbackconnections of the prior art. Further, such D. C. coupled diodes areemployed to flip a trigger one Way only, that is, either to an on or toan off condition but are incapable of flipping the trigger to both ofthese conditions at diiierent times.

Another object of the present invention is to provide simple means foraltering the normal cascade operation of a series of triggers, saidmeans comprising a single diode. in order to employ a single diode onlyandobtain conversion from cascade to operation in another radix, diodecoupling cannot be employed since as is obvious from the prior art, aplurality of such diodes arerequired to achieve the result desired. inorder that a single diode Ice only will suffice, the novel diode gatingmeans, as disclosed in applicants copending application Serial No.197,960 filed November 28, 1950 is employed in the mannor as set forthin detail below.

Still another object is to provide novel means for altering the normalcascade operation of a series of triggers said means comprising a diodegate, A. C. coupled to one of the triggers of the cascade and controlledby another of the triggers of the cascade.

Another object is to provide a novel counter comprising four cascadeconnected triggers and A. C. coupled diode gate means for converting thenormal 1-2-4-8 operation of the triggers to 1-2-2-4 operation.

A further object is to provide a novel counter comprising four cascadeconnected triggers and A. C. coupled diode gating means for convertingthe normal 1-2-4-8 operation of the triggers to 1-1-2-5 operation.

Another object is to provide a novel counter comprising four cascadeconnected triggers and A. C. coupled diode gating means for convertingthe normal binary operation to duo-decade operation.

Still another object is to provide a novel counter comprising fourcascade connected electronic triggers and A. C. coupled diode gatingmeans for converting the normal 1-2-4-8 operation to 1-2-4-4 operation.

Another object is to provide a novel counter comprising four cascadeconnected electronic triggers and A. C. coupled diode gating means forconverting the normal 1-2-4-8 operation to 1-2-2-6 operation.

Still another object is to provide a novel electronic counter comprisingfour cascade connected electronic triggers and A. C. coupled diodegating means for converting the normal 1-2-4-8 operation to 1-1-3-6operation.

Another object is to provide a novel counter comprising a plurality ofelectronic triggers connected in cascade and means comprising a singlediode only, for converting the normal binary operation to decadeoperation.

A still further object is to provide a novel counter comprising aplurality of cascade connected electronic triggers and a single diodeonly, for converting the normal binary operation to duo-decimaloperation.

Other objects of the invention will be pointed out in the followingdescription and claims and illustrated in theaccompanying drawings,which disclose, by way of example, the principle of the invention andthe best mode, which has been contemplated, of applying that principle.

In the drawings: t

Fig. 1 is a wiring diagram of a pair of cross-coupled triodes comprisingan electronic trigger employed in the counter.

Fig. 2 is a wiring diagram of one embodiment of a decade counterillustrating the circuit connections among triggers of the typeillustrated in Fig.1.

Fig. 3 is a diagrammatic block diagram illustration of the device ofFig. 2.

Fig. 4 isa diagrammatic block diagram illustration, generally similar toFig. 3, but illustrating another embodiment of adecade counter.

Fig. 5 is a wiring diagram of an embodiment of a duodecimal counterillustrating the novel diode gating means andthe circuit connectionsamong triggers of the type illustrated in Fig. 1.

Fig. 6 is a diagrammatic block diagram illustration of the device ofFig. 5. I

Fig. 7 is a diagrammatic block diagram illustration, generally similarto Fig. 6, but illustrating another embodiment of a duo-decimal counterand;

Fig. 8 is a diagrammatic block diagram illustration, generally similarto Fig. .6, but illustrating still another embodiment of a duo-decimalcounter.

Referring to the drawings and more particularly to,

Fig. 1, there is shown the details of the cross-coupling circuits for apair of triodes to form an electronic trigger, the circuit within therectangular block illustrating the cir cuits actually included in theblocks of the diagrammatic block diagram figures.

In Fig. l, the trigger comprises an electronic trigger of the nowwell-known Eccles-Jordan type comprising a pair of cross-coupled triodesand 11. These are illustrated as being contained within a singleenvelope and may, for example, comprise a 616 type tube but it is to bespecifically understood that they may comprise individual tubes if sodesired and as is now well known in the art need not necessarilycomprise triodes. Further, throughout the specification, certain typesof elements and certain values of components are given but it is to beunderstood that these may be varied within the ambits obvious to thoseskilled in the art, the values and types specified herein having beenfound particularly efiicacious in the circuits as disclosed.

In Fig. 1, plate P1 of triode 10 is coupled via line 12 and a resistor13 and condenser 14, in parallel, to the grid G2 of triode 11. The plateP2 is similarly coupled to the grid G1 of triode 10. A value of theresistor 13 which has been found suitable is 200K ohms while thecondenser 14 may assume a value of 100 microfarads. The cathodes of thetwo cross-coupled triodes are joined and connected to ground, as shown.The grid G1 is coupled to the oil input via a condenser 15 and the gridG2 is coupled to the on input via a condenser 16, a suitable value forthe condensers 15 and 16 being 40 micromicrofarads each. The grids G1and G2 are connected via resistors 17 and 18, respectively, to a biassource of minus 100 volts, the values of each of these resistors being200K ohms. Plate P1 is connected to a source of +150 volts via a pair ofresistors 19 and 20, in series, a suitable value for resistor 19 being12K ohms and of resistor 20 being 7.5K ohms. The plate P2 is similarlyconnected to the +150 volt source by means of two similar resistors inseries, as shown. When a trigger is employed for diode gate control, asdescribed later, more suitable values of each of the resistors 19 and 20has been found to be 10K ohms each.

As illustrated in Fig. 1, each of the plates P1 and P2 may be providedwith a full plate output while each plate is also provided with a tap inthe output. As shown, these taps are employed in the interconnectionsamong the triggers, as will be described presently.

As is well known in the art, a trigger of the Eccles- Jordan type hastwo states of stability. In one state, for example, the triode 11 willbe conducting while triode 10 will be cut oil. This may be produced byapplying a negative pulse to the input labelled OE and in the instantapplication this state of equilibrium in which the triode 10 isnon-conducting, as produced by application of such a negative pulse, andwith triode 11 conducting, is

herein called the off state of the trigger. On the other hand, withtriode 11 cut off, such as may be produced by a negative pulse appliedto the input On and with triode '10 conducting, this state ofequilibrium is herein called the on state. These states of equilibriumare so identified in order to simplify the succeeding description of theoperation of the device.

A plurality of triggers, herein shown as four triggers -of the type asshown in detail in Fig. 1, are illustrated in "Fig. 2, generallyconnected in cascade.

When so connected the operation of the four triggers may be referred toas 1-2-4-8 operation, since one pulse turns on the first trigger(assuming that all of the triggers are initially off) two pulses willturn 0 the first trigger and as it goes off it flips on the secondtrigger, etc. Four pulses are required to turn on the trigger followingthe In order to render such a cascade useful in the normal commercialsystems of counting such as, for example, the decimal system in thiscountry or the duo-decimal system in the sterling area, the normalbinary operation of four such cascade connected triggers must bealtered. Such alteration may change the number of pulses required toinitially turn on a trigger of the series but does not affect theweight" of any one trigger in a particular hookup. Thus, if only thefirst trigger is on, the counter count is 1. If the first trigger is onand the second trigger is on, the counter count depends upon the weightattached to any trigger above the first, which is on. That this variesfor different counters will be obvious from the following descriptionbut, as previously stated, with any one particular counter hookup theweight remains fixed for each trigger which is on, as will be apparentfrom the following.

Novel means are now provided for producing in an extremely simple mannerthe alteration, of a generally cascade connected series of triggerswhich would normally operate in pure binary, to operation in the decimalor duo-decimal system.

Referring to Fig. 2, there is illustrated therein four triggers of thetype of Fig. 1 and labelled generally T1, T2G, T2 and T4. These triggersare generaly connected in cascade whereby in the normal cascadeoperation the turning off of a preceding trigger will flip thesucceeding trigger either on or off depending upon its status at thetime. Assuming that all of the triggers have been reset off so that eachof the right hand triodes of each of the triggers is conducting, asindicated by the small circles near the right hand side of eachenvelope. A negative pulse applied to the counter input is also appliedto both of the grids of trigger T1 and will flip trigger T1 on. The pluspulse thus produced on line 21 has no effect, since these triggers willoperate only upon the application of negative pulses, with theparameters as indicated.

The second pulse applied to the input of the counter will flip triggerT1 ofl. The negative pulse thus produced on line 21 is applied to thegrid G2 only of trigger T2G to thus flip this trigger on. This in turnproduces a plus pulse on line 22, which has no effect on trigger T2.

The third pulse applied to the counter input flips trigger TI on, withno further efiect.

The fourth pulse applied flips trigger T1 off.

The negative pulse produced on line 21 is no longer effective to fliptrigger T2G, since line 21 is connected only to the grid G2 of thistrigger and can only flip this trigger on. When trigger T2G waspreviously flipped on so that its right hand triode becamenon-conducting, the voltage level at point 23 in the plate circuit wasraised which, via the resistor R and line 22 increases the voltage levelapplied to the plate of the diode Dia. This diode may, for example,comprise a G. E. 1N52 crystal diode, although as pointed out inapplicants copending application Serial No. 197,960, filed November 28,1950, with certain parameters a tube type diode may be employed.

As stated above, the fourth negative pulse applied to the counter inputflips trigger T1 off but the negative pulse applied va line 21 isineffective to flip the trigger T2G since this trigger can only beflipped on and it is already on. However, since the voltage level on theplate side of the diode Dio is now raised, this negative pulse appliedvia line 21 to the cathode of this diode is effective, via the circuitcomprising the resistor R, the diode Dio and its A. C. coupling viacondenser K2, for example, in the manner as described in said copendingapplication Serial No. 197,960, to apply via this condenser K2 anegative pulse to the grid G2 of trigger T2 to flip T2 on. Thus, inelfect, as set forth in detail in said copending application, the diodeDio compares the voltages on the two sides of the diode and only whensuch com parison requires it, the gating action of the diode is employedto apply a negative pulse via the condenser K2,

for example, to the grid G2 of trigger T2 to flip' it on. The diode D'ioalways compares the voltages on the two sides thereof and flips its A.C. coupled trigger, when and only when such flipping is required, sothat no unnecessary flipping of its controlled trigger is ever produced.Thus, the fourth counter input pulse results in triggers T26 and T2 bothbeing on. Since the weight of each of these triggers is 2, the totalcount represented at this time for the entire counter is the sum ofthese two on conditions or a total of 4.

The fifth counter input pulse flips trigger T1 on, with no furthereffect.

The sixth counter input pulse flips T1 off which is effective via line21 and the A. C. coupled diode network, which this time includes thecondenser K1, to apply a negative pulse to the grid G1 of the trigger T2to flip T2 off. As T2 flips off, it produces a negative pulse on line24, which in turn flips trigger T4 on. Thus the sixth counter inputpulse results in triggers T2G and T4 being on an the sum of the weightsof these two triggers equals 6, which is the correct total count.

The seventh counter input pulse flips T1 on, with no further effect.

The eighth pulse flips T1 off which, in turn, via line '21 and the A. C.coupled diode Bio and condenser K2 flips trigger T2 on. Thus the eighthcounter input pulse results in trigger T2G being on, T2 being on" and T4also being on, which represents a total count of 8.

The ninth counter input pulse flips TI on, with no further effect. 7

The tenth counter input pulse flips trigger T1 off. The negative pulsethus produced on line 21 acts via the A. C. coupled diode gate Dio andcondenser K1 to flip trigger T2 off. As T2-goes off, it produces anegative pulse on line-24 which flips T4 off. As trigger T4 goes off,the engative pulse on line 25 is fed back to the grid G1 of the triggerT2G, flipping this trigger off so that this tenth counter input pulsereturns all triggers to the off condition which, as set forth above,'isthe normal reset condition. The line 25 also serves as an output fromthe counter so that a negative pulse is available at the output, on theth counter input pulse, as indicated in Fig. 2. This may be applied inthe form of a carry to another counter if several of these counters areconnected in a chain or as part of an accumulator.

There is illustrated in Fig. 3 the same identical counter as in Fig. 2the triggers of the counter being shown diagrammatically in block formin order to more concisely highlight the interconnections among thetriggers, as illustrated in detail in Fig. 2. The operation of thedevice as illustrated in Fig. 3 is obviously identical to that describedabove in connection with Fig. 2.

Referring to Fig. 3 and to the following Table 1, the operation of thecounter, shown in detail in Fig. 2, is easily followed. off while an Xindicates that a trigger is on. Table 1 and Fig. 3 together comprise ineffect an extremely brief rsum of the operation in Fig. 2, as set forthin detail above.

Table 1 Triggers Counter Input Pulses T1 TZG T2 T4 0 O O O X 0 O' O 0 X0 O X X 0 O O X X O X X X ,0 0 X 0 X X X 0 X 0 X X X X X X I X O 0' O OIn Table 1, an 0 indicates that a trigger is Referring'to Fig. 4, thereis illustrated therein a modification of the decade counter of Fig. 2.The scheme of illustration employed in Fig. 3 is also employed in Fig. 4in order to more sharply accentuate the differences between theserespective circuits. I

Referring to Fig. 4, there is again illustrated, in block form, fourtriggers generally connected in cascade. The weight to be given to eachtrigger is indicated by the number following the letter T, the triggerlabelled TlG indicating not only that this trigger has a weight of 1 butalso that this is the trigger which controls the gating operation of thediode. Fig. 4 taken together with the following Table 2 set forthclearly the operation of this embodiment of a decade counter.

Table 2 Triggers Counter Input Pulses TiG T1 T2 T5 0 O O 0 X 0 O 0 X X 00' X 0 X 0 X X X 0 O 0 0 X X 0 0 X X X 0 X X 0 X X X X X X 0 0 0 0Referring to Fig. 4 and to the above Table 2, the first counter negativeinput pulse turns on trigger TlG. The second counter input pulse cannotturn off TlG since the counter input is connected only to the grid ofthe right handtriode and-not to the grid of the left hand triode. Whentrigger T16 is flipped on," the'voltage level on the plate of diode Diois increasedsince the right hand triode is rendered non-conductive.Therefore, upon application of the second counter input pulse, thevoltage on the cathode of diode Dio'is sharply reduced and by the nowwell understood gating action of diode Dio, flips on trigger T1, asindicated in Table 2. The third counter input pulse also has no effecton trigger T1G but produces flipping oif of trigger T1, as indicated inTable 2', which in turn flips on trigger T2. The fourthcounter input Ipulse operation will be clear from Table 2.

The fifth counter input pulse does not directly affect trigger TlG butdoes flip trigger T1 off by means of the gating action of diode Di0.'This, in turn, flips off trigger T2, which does two things. It flips ontrigger T5 and also, via line 26, applies a negative pulse to the gridof the left hand triode of trigger T1G to flip it off, all as indicatedin Table 2.. The sixth counter input pulse flips trigger TlG on butsince .triggerTlG was previously off thus lowering the voltage level onthe plate-of diode Did, no gating action ensues and trigger T1 remainsoff, as'indicated in Table 2. The seventh counter input pulse isineffective to flip trigger TlG but since the sixth pulse left thistrigger on, the voltage level was raised on the plate of diode Dio, sothat this seventh negative input pulse is effective, by means of thediodegating action, to flip trigger T1 on. The eighth pulse is effectiveto flip T1 off, as indicated in Table 2, whichin turn flips T2 on. Theninth counter input pulse flips T1 on by means of the gating action ofdiode Dio.

The tenth counter input pulse flips T1 off which, in turn, flips T2 off.When T2 is thusly flipped off, it performs two operations. It flips offT5 and also, via line 26, applies a negative pulse to the grid of theleft hand triode of trigger TlG, to flip this trigger off, all asindicated in Table 2. Thus the device of Fig. 4 is returned to normalreset condition and anoutput pulse ,is produced at the output oftriggerT5,.asindicated in Fig. 4, upon application of the tenth counterinput pulse to the input of the counter.

Referring to Fig. 5, illustrated therein is a counter generally similarto that of Fig. 2 but one in which the normal Table 3 Triggers CounterInput Pulse T1 T2 T46 T4 O O O X 0 0 -O O X 0 O X X 0 O 0 O X 0 X 0 X 00 X X 0 X X X 0 O O X X X 0 X X 0 X X X X X X X 0 O O O Referring toFig. and Table 3, the first negative counter input pulse flips T1 on.The second counter input pulse flips T1 off which in turn applies anegative pulse via line 27 to the grids of T2, to flip T2 on. Theoperation on the third, fourth, fifth, sixth and seventh pulses is asclearly shown in Table 3.

The eighth counter input pulse flips T1 off which applies a negativepulse to line 27 to flip T2 off and T2 in going off applies a negativepulse via line 28 to the 'grid of the right-hand triode only, of triggerT4G but since this trigger is already on, it merely remains on. When T48was turned on, it applied an increased voltage level to the plate ofdiode Dio so that this negative pulse now applied via line 28 to thecathode of Dio is effective by the gating action of Dio, line 29 andcondenser K2 to apply a negative pulse to the grid of the right-handtriode of T4, to flip it on, as indicated in Table 3.

The ninth counter input pulse turns on T1, as shown in Table 3. Thetenth pulse flips T1 01f which in turn flips T2 on. The eleventh pulseturns T1 on.

Upon application of the twelfth counter input pulse, T1 is turned oif.This applies a negative pulse via line 27 to flip T2 ofl. T2 in going 0applies a negative pulse via line 28 to the grid of the right-handtriode of T4G but since T4G is already on, this pulse has no efiect.With "MG on, the voltage level on the plate of Dio is relatively high sothat the negative pulse on line 28 applied to the cathode of Dir) iseffective by means of the diode gating action of Dio, line 29 andcondenser K1, to apply a negative pulse to the grid of the left-handtriode of T4, turning T4 off. As T4 goes off, it applies a negativepulse via line 30 which serves as an output to the next duo-decimalcounter. By means of line 3!}, a negative pulse is also fed back to thegrid of the left-hand triode of T4G turning this trigger off. Thus, onthe twelfth counter input pulse, all of the triggers are restored to thenormal reset condition and an output pulse indica tive of a count of 12is available at the output, as indicated in Fig. 5. s

Fig. 6 is a diagrammatic block diagram illustration of the circuit ofFig. 5 high-lighting the interconnections among the respective triggers.

Fig. 7 is a diagrammatic block diagram illustration'of anotherembodiment of Lhe duo-decimal counter, generally of the type-of Fig. 5,but illustrated diagrammatically along the lines of Fig. 6 in order tosuccinctly set forththe distinctions. Referring to Fig. 7 and to thefollowing Table 4, the operation will now be described:

Table 4 Triggers 10 Counter Input Pulse T1 T2G T2 T6 0 O O O X 0 0 O O X0 O X X 0 0 O X X 0 X X X 0 O O 0 X X 0 O X 0 X 0 X X X 0 X 0 X X X X XX X 0 O O O The first counter negative input pulse flips T1 on." Thesecond pulse flips T1 off which applies a negative pulse via line 31 tothe grid of the right-hand triode of T2G to flip it on. With T2G on, thevoltage level on the plate side of the diode Dio is raised. The thirdpulse turns T1 on, with no further effect, as is obvious from Table 4.

The fourth pulse flips T1 off. The negative pulse thereby produced online 31 is ineflective to flip trigger T2G, since this trigger isalready on. However, this negative pulse on line 31 is applied to thecathode of diode Dio whose plate voltage level is now relatively highsince TZG is on. Thus by the diode gating action of Dio, a negativepulse is applied via line 32 to the grids of T2, to flip it on.

The fifth pulse flips T1 on, with no further effect.

The sixth input pulse flips Tll off. The negative pulse thereby producedon line 31 has no effect on TZG since it is already on but the diodegating action of Dio flips T2 off. As T2 flips 01f, it applies anegative pulse via line 33 to flip T6 on in normal fashion. Also, vialine 33, a negative pulse is applied to the grid of the lefthand triodeof T2G, to flip it oif.

The seventh pulse flips TI on, with no further effect. The eighth pulseflips T1 on which in turn via line 31 flips T2G on so that the voltagelevel on the plate of Dio is raised preparing it for gating action. Theninth pulse turns T1 on, with no further effect. The tenth pulse turnsT1 ofi'. The negative pulse thereby pro duced on line 31 has no effecton TZG since it is already on. By the diode gating action of Dio, anegative pulse is applied via line 32 to flip T2 on. The eleventh pulseflips TI on with no further effect.

The twelfth counter input pulse flips T1 of The negative pulse on line3i has no effect on T 2G since it is already on. This negative pulse online 31, however via the gating action of diode Die and line 32 flips T2off. T2 in going oif applies a negative pulse via line 33 to the grid ofT6 to flip it off thus producing a negative pulse on the output. Thenegative pulse on line 33 is also applied to the grid of the left-handtriode of trigger T2G, flipping it off, so that the counter is returnedto the normal reset condition upon application of this twelfth counterinput pulse.

Referring to Fig. 8, diagrammatically disclosed therein is anotherembodiment of a duo-decimal counter, generally of the type of Fig. 5 butagain illustrated diagrammatically in block diagram form along the linesof Figs. 6 and 7. By reference to Fig. 8 and the following Table 75 5,the operation of the device will be clear:

Table Triggers Counter Input Pulse T1 G T1 T3 T6 0 O O O X 0 O O X X 0 00 O X 0 X 0 X 0 X X X 0 O O O X X 0 O X X X 0 X 0 O X X X 0 X X X X X X0 O O O The first counter negative input pulse flips TlG on. With T1Gon, the voltage level at the plate of diode Dio is relatively increasedso that when the second counter input pulse is applied, it is effective,by means of the diode gating action of diode Dio, to apply a negativepulse, via line 34, to flip T1 on. This second counter input pulse isineffective to flip T1G since it is applied only to the grid of theright-hand triode thereof and TIG is already on, by means of the firstcounter input pulse. The third input pulse by means of the diode gatingaction of diode Dio applies a negative pulse via line 34 to flip -T1off. This'applies a negative pulse via line 35 to flip T3 on and alsovia line 35 to flip TIG o The fourth input pulse flips TlG back on, sothat again the relative voltage level at the plate side of Dio is raisedso that upon application of the fifth counter input pulse, T1 is flippedon" by the gating action of diode Dio. The sixth pulse has no directeifect on TlG but by means of the gating action of diode Dio flips T1off which in turn via line 35 flips T3 off which in turn via line 36flips T6 on. The negative pulse on line 35 is also fed back to the gridof the left-hand triode of T1G to flip it off. The seventh pulse flipsTIG on, so that diode 'Dio, on the eighth pulse flips TI on. The ninthpulse has no direct effect on T 16 but by means of the gating action ofdiode Dio flips T1 off which via line 35 flips T3 on and TIG oif. Thetenth pulse flips TlG on so that the Dio is effective on the eleventhpulse to flip T1 on.

The twelfth counter input pulse has no direct effect on TIQ but by meansof the diode gating of diode Dio flips T1 off. This in turn via line 35flips T3 off which via line 36 flips T6 off to produce a pulse on theline marlged Output on the twelfth input pulse to the counter. Thenegative pulse on line 35 also flips TIG off so that the counter hasbeen reset to the original reset condition.

it is thus seen that there are disclosed two general types of counters.One comprises a plurality of four cascade-connected electronic triggerswhose normal binary operation is changed to decade operation by means ofdiode gating means which compare the voltages on two sides of the diodeand flip a trigger when and only when the comparative voltages requiresuch flipping. Thus unnecessary operation of any triggers is avoided.Similarly by employing the novel diode gating means, there is noblocking and no partial flipping of triggers and the number of triggersflipped in any decade run is maintained at a minimum. Various patternsof decade operation are disclosed.

Similarly, a plurality of patterns of duo-decimal operation of a similargroup of four cascade-connected electronic triggers are disclosed,utilizing the high efliciency, speed of operation and selective triggeroperation produced by diode gating.

-While there have been shown and described and pointed out thefundamental novel features of the invention as applied to a plurality ofembodiments, it will be understood tha riou omi sion n u s u n andchanges in the form and details of the device illustrated and in itsoperation may be made by those skilled in the art, without departingfrom the spirit of the invention. It is the intention, therefore, to belimited only as indicated by the scope of the following claims.

What is claimed is:

1. An electronic counter comprising at least four bistable devicesconnected in cascade, an input and an out put for said cascade and meansfor altering the number of pulses required to be applied to said inputto produce an output, said alteration being from the number that wouldbe required during unaltered straight cascade operation to a lessernumber, said means for altering comprising one single diode onlycontrolled by a single one only of said devices for operation by a pulseto selectively flip or not to flip one other device only in accordancewith the on or off status of said controlling device.

2. An electronic counter comprising at least four cascade-connectedbi-stable devices, an input and an output for said cascade, said outputbeing effective under control of a selected number of pulses applied tosaid input, and means for altering the number of pulses required toproduce such an output said alteration being from the number that wouldbe required during unaltered straight cascade operation to a lessernumber, said means for altering comprising one single diode onlycontrolled by a single one only of said bi-stable devices to selectivelyproduce or not to produce operation of another bi-stable device undercontrol of an operating pulse in dependence upon the on or off conditionof said controlling bi-stable device, said diode means being A. C.coupled to the controlled bi-stable device.

3. A counter comprising at least four cascade-connected bi-stabledevices, a source of pulses for operating said bi-stable devices, aninput to said counter to which said pulses are applied, an output forsaid counter effective upon application of a predetermined number ofpulses to said input which number is less than the number which would berequired to produce an output upon straight cascade operation of saidbi-stable devices, and means for fixing said predetermined number ofpulses required to produce an output comprising voltage comparing means,said means comprising one single diode only operable only with apredetermined dilference of potential level on the two sides of saiddiode produced by the operation of two bi-stable devices only of saidbi-stable devices for operating one of the other bi-stable devices ofthe eascade out of its normal cascade operation.

4. A counter comprising at least four cascade-connected bi-stabledevices, and means for altering the number of pulses required to beapplied to the input of said counter to produce an output, saidalteration being from the number required for unaltered straight cascadeoperation to a lesser number, and including, one single diode onlycontrolled by two bi-stable devices only of said cascade comparing theelectrical status of one of said two bi-stable devices and that of theother of said two bi-stable devices, said single diode being eflectiveto flip a succeeding bi-stable stable device only when the status ofsaid two bi-stable devices is diiferent.

5.- A counter comprising a plurality of cascade-connected electronictriggers and a coupling device between two of said triggers comprising adiode, a resistor connected to one side of said diode, one of saidtriggers while being flipped comprising a source of rapidly varyingpotential to be applied to the other side of said diode and the otherone of said two triggers comprising means for altering the level ofpotential applied through said resistor to said one side of said diodeupon alteration of the on and oif status of said one trigger and meansincluding a capacitor connected between said diode and resistor andconnected to still another trigger for-delivering an operating voltageupon assumption of one status by said other trigger and production ofsaid rapidly varyns vPote ti l by sa d n t ss 6. A counter comprising aplurality of cascade-connected electronic triggers and a coupling devicebetween two of said triggers comprising a diode, a resistor connected toone side of said diode, one of said triggers being connected to theother side of said diode whereby upon operation of said one trigger arapidly varying potential is applied to said diode, the other one ofsaid two triggers being connected to the other end of said resistor andoperable to produce a change in the level of potential upon said oneside of said diode upon alteration of the on and oil conditions of saidone trigger and means including a capacitor for connecting the pointbetween said one side of said diode and said resistor to a third one ofsaid triggers whereby said third trigger is flipped when the level ofpotential on one side of said diode is increased and said rapidlyvarying potential is applied to the other side thereof while said thirdtrigger remains in its then status when the level of potential on saidone side of said diode is relatively low.

7. A counter comprising a plurality of cascade-connected electronictriggers each operable to two conditions of stability and a couplingdevice for certain of said triggers comprising a diode connected at oneside to one of said triggers whereby upon operation of said trigger toone condition of stability a rapidly varying potential varying inonedirection is applied to said side of said diode, a network comprising aresistor connected to a condenser, means connecting one end of saidnetwork to another of said triggers and the other end of said network toa third one of said triggers and the other side of said diode to theconnection between said resistor and condenser, said other end of saidnetwork being operable to deliver a flipping pulse to said third triggeronly upon assumption of a chosen status of said second trigger andproduction of said varying potential by the operation of the first ofsaid triggers.

8. A counter comprising at least four cascade-connected bi-stabledevices, and means for coupling certain ones only of said bi-stabledevices to produce by the action of said means, an output from saidcounter and comprising one single A. C. coupled diode only connected atone side to one of said bi-stable devices, at the other side to a secondof said bi'stable devices and operable to produce a flipping pulse to athird one of said devices via said A. C. coupling, only upon assumptionof one condition of stability by the second of said devices but not theother condition of stability and upon operation of the first of saiddevices to produce a varying potential rapidly varying in one chosendirection but not when varying in the other direction.

9. A counter comprising a plurality of four cascadeconnected bi-stabledevices and means to produce by the action of said devices an outputfrom said counter and comprising a circuit coupling the first, secondand third of said devices including one single diode only, meansconnecting one side of said diode to a plate output of one device, meansconnecting the same side of said diode to a control element of a secondof said devices, means, including a resistor, connecting the other sideof said diode to a plate output of said second device and means couplingsaid other side of said diode to a control element of the third of saiddevices.

10. An electronic counter comprising a plurality of fourcascade-connected bi-stable devices and means for altering the normalcascade operation of said bi-stable devices to produce by the action or"said devices an output from said counter and comprising a circuitwhereby operation of the first of said devices alone to on conditionrepresents a count of one, operation of the second of said devicesalone, to on condition, a count of two, operation of the third of saiddevices alone, to on condition, a count of two, and operation of thefourth of said devices to on condition, a count of four, the combined onconditions of any of the four representing the sum of the sole counts,said means comprising a single A. C.-coupled diode only,

D. C. connected to two of said devices and A. C.-coupled to another oneof said devices.

11. A counter comprising a plurality of four cascadeconnected triggers,means including a single diode and resistor in series connected betweenthe plates of two successive triggers and A. C-coupling means connectedat one end between one side of said diode and its series re sistor andat its other end to a control element of a third of said triggers andincluding means connecting the output of said counter and a controlelement of the second trigger of said series.

12. A counter comprising a plurality of four cascadeconnected electronictriggers and means for coupling two of said triggers comprising a singlediode, a resistor'in series with said diode, the free end of saidresistor being coupled to a plate output of the first one of saidtriggers, a source of pulses for said counter, means applying saidpulses to one of said triggers and to one side of said diode, a tapbetween the other side of said diode and its series resistor and meansA. C. coupling said tap with a control element of another of saidtriggers.

13. A device as in claim 12, said A. C. coupling means interconnectingsaid tap and both control elements of said other trigger.

14. A counter comprising a plurality of four cascadeconnected triggersand means for coupling the first and second of said triggers comprisinga single diode, resistance means connecting one side of said diode to aplate output of the first of said triggers and a condenser coupling saidsame side of said diode to the control elements of the second of saidtriggers, a source of pulses to be counted and means connecting saidsource to one control element only of said first trigger and to theother side of said diode.

15. A counter comprising four electronic triggers connected in cascade,a source of input pulses, means interconnecting an output of the thirdof said triggers and an input of the first of said triggers, meansapplying said input pulses to another input of said first trigger, asingle diode, means applying said pulses to one side of said diode, aresistor connected at one end to one side of said diode and at the otherend to an output of said first trigger and means A. C. coupling saidsame side of said diode and the inputs of the second of said triggers.

16. A counter comprising four cascade-connected electronic triggers andmeans for altering the normal cascade operation of said triggers toproduce by the action of said means an output from said counter upon theapplication of a number of input pulses less than the number required toproduce an output with normal cascade operation, whereby the oncondition of the first trigger alone, represents one, the on conditionof the second trigger alone, represents one, the on condition of thethird trigger alone, represents two and the on condition of the fourthtrigger alone, represents five, said means comprising one single A.C.-coupled diode only coupling two only of said triggers.

17. A counter comprising four cascade-connected electronic triggers andmeans for altering the normal cascade operation comprising a singlediode, means connecting one side of said diode to an output of thesecond trigger, means including a resistor connecting the other side ofsaid diode and the output of the third of said triggers and A. C.coupling means connected between said resistor and said other side ofsaid diode and to an input of the fourth of said triggers.

18. A device as in claim 17 and including means connecting the output ofsaid counter and an input of the third of said triggers.

19. A counter comprising four cascade-connected electronic triggers andmeans for altering the normal cascade operation of said triggers toproduce by the action of said means an output from said counter upon theapplication of a number of input pulses, less than the number requiredto produce an output with normal cascade operation so that the oncondition of the first of said triggers alone, represents one, the oncondition of the second of said triggers alone, represents two, the oncondition of the third of said triggers alone, represents four and theon condition of the fourth of said triggers alone, represents four, saidmeans comprising one single A. C. coupled diode only coupling two onlyof said triggers and operable to operate another of said triggers out ofits normal cascade operation.

20. A device as in claim 19 and including a connection between an outputof the fourth of said triggers and a single input only of the third ofsaid triggers.

21. A device as in claim 19, said diode being connected at its cathodeside to an output of said second trigger and at its plate side to anoutput of a third of said triggers and to both inputs of said fourthtrigger.

22. A counter comprising four cascade-connected electronic triggers andmeans for altering the normal cascade operation of said triggers so thatthe on condition of the first of said triggers alone represents one, theon condition of the second of said triggers alone, represents two, theon condition of the third of said triggers alone, represents four andthe on condition of the fourth of said triggers alone, represents four,said means comprising a single A. C.-coupled diode coupling two of saidtriggers and operable to operate another of said triggers out of itsnormal cascade operation, said diode being connected at its cathode sideto an output of said second trigger and at its plate side to an outputof a third of said triggers and to both inputs of said fourth trigger,said connection between the' plate side of said diode and said output ofsaid third trigger being resistive and said connection between saidplate side of said diode and said fourth trigger being capacitive.

23. A counter comprising four cascade-connected bistable devices andmeans for altering the normal cascade operation to produce by the actionof said device an output from said counter upon the application of anumber of input pulses less than the number required to produce anoutput with normal cascade operation, said means comprising one singlediode only, means connecting one side of said diode to an input of thefirst bi-stable device and to an input of the second bi-stable deviceand means connecting the other side of said diode to an output of saidsecond bi-stable device and to an input of the third bistable device.

24. A counter comprising four cascade-connected bistable devices andmeans for altering the normal cascade operation comprising a singlediode, means connecting one side of said diode to an output of the firstbi-stable device and to an input of the second bi-stable device, meansconnecting the other side of said diode to an output of said secondbi-stable device and to an input of the third bi-stable device, one ofsaid last two connections being resistive and the other capacitive.

25. A device as in claim 24, and means connecting an output of saidthird bi-stable device and an input of said second bi-stable device.

26. A counter comprising a plurality of four cascadeconnected triggersand means for altering the normal cascade operation to produce by theaction of said means an output from said counter upon the application ofa number of input pulses, less than the number required to produce anoutput with normal cascade operation whereby the on condition of thefirst trigger alone, represents one, the on condition of the secondtrigger alone, represents two, the on condition of the third triggeralone, represents two and the on condition of the fourth trigger alonerepresents six, said means comprising one single diode only D. C.coupling two of said triggers and A. C. coupling a different two of saidtriggers.

27. A counter comprising a plurality of four cascadeconnected triggersand means for altering the normal cascade operation whereby the oncondition of the first trigger alone represents one, the on condition ofthe second trigger alone represents two, the on condition of the thirdtrigger alone represents two, and the on condition of the fourth triggeralone represents six, said means comprising a single diode, D. C.coupling tw o of said triggers and A. C. coupling a different two ofsaid triggers, said D. C. coupling means comprising a direct connectionbetween one side of said diode and an input of one trigger and theoutput of another, and a resistor, connected between the other side ofsaid diode and an output of one of said two triggers, and said A. C.coupling comprising a condenser coupling the tap between said resistorand diode and an input of another of said triggers.

28. A device as in claim 27, and including a connection between anoutput of the third trigger and an input of the second.

29. A counter comprising four cascade-connected bistable devices andmeans for altering the normal cascade operation comprising a singlediode, a source of pulses to be counted, means connecting said source toone side of said diode and to one input of the first of said bi-stabledevices, and a resistive connection between the other side of said diodeand one of said bi-stable devices and a capacitive connection betweensaid other side and another of said bi-stable devices.

30. A device as in claim 29, said resistive connection being between anoutput of the first of said triggers and said other side of said diodeand said capacitive connection being to an input of the second of saidtriggers.

31. A device as in claim 30, and a connection between an output of saidsecond trigger and an input of said first trigger.

32. A counter comprising four cascade-connected triggers and means foraltering the normal cascade operation whereby the on condition of saidfirst trigger alone, represents one, the on condition of the secondtrigger alone, represents one, the on condition of the third triggeralone, represents three and the on condition of the fourth triggeralone, represents six, said means comprising a single diode, a source ofpulses to be counted, means connecting said source to one side of saiddiode and to an input of the first of said triggers, and meansresistively and capacitively connecting the other side of said diode totwo others only of said four triggers respectively.

33. A device as in claim 32, said resistive connection being to anoutput of the first trigger and said capacitive connection to an inputof the second of said triggers.

34. A device as in claim 33, said capacitive connection being to bothinputs of said second trigger.

35. A device as in claim 33 and including a connection from an output ofsaid second trigger to an input of said first trigger.

36. A selective transfer unit for use in binary com- 'puting andcounting devices having a plurality of multivibrator storage units, eachof said storage units having two oppositely designated anodes and atriggering input terminal; said transfer unit comprising impedanceelements, including two resistors, a rectifier, and a capacitorconnected to a common junction point in star relationship and providingat the respective ends of said impedance elements opposite said junctiona first resistor terminal for connection to an anode of one of saidstorage units, a second resistor terminal for connection to a source ofdirect potential, a rectifier terminal for connection to the triggeringinput terminal of another of said storage units, and a capacitorterminal for transmitting triggering pulses.

References Cited in the file of this patent UNITED STATES PATENTS (Otherreferences on following page) 15 UNITED STATES PATENTS Moore Nov. 21,1950 Palmer Jan. 2, 1951 Heising Jan. 30, 1951 Bergfors Jan. 30, 1951Grosdofi Feb. 6, 1951 Crenshaw Apr. 24, 1951 Hadfield May 15, 1951 BakerNov. 13, 1951 16 Mumma Feb. 5, 1952 Rench Apr. 1, 1952 Moore Apr. 8,1952 Schmidt Mar. 10, 1953 Wolfe July 7, 1953 OTHER REFERENCES Proc. ofthe I. R. E., volume 37, No. 7; Predetermined Electronic Counter, byGossick, July 1949.

